Forgive me if this is a bit slap dash posting it from my phone in a rush as I have to be somewhere.
Asus Strix Nvidia GTX 1080 for £575 (yet to confirm with money taken from my credit card) from amazon.fr
This is the cheapest I've seen this card, ever.
I missed 2 1080 deals around black Friday and was gutted so waited and waited and finally this. I think this is probably the best deal you'll find especially before Xmas.
As for Amazon.fr I followed advice from previously posted info on this site. Choose to pay in euros at checkout. Use a Mastercard to pay if possible. Final price to pay was about 684 euros which according too Google is £575.
The asus Strix is arguably the best version of the 1080 so for me it was worth paying more than the other deals have been (previously £500 and £530)
Also worth noting the MSI GAMING X 1080 is the same price. The PNY custom cooled card is also €640 so probably €648 inc delivery. If you prefer them cards then they're also great deals.
Will probably edit this later to make it a bit neater.
Happy deal hunting!